Substantial effort has been put forth on the development of new and more sustainable energy supplies, as well as efforts to increase energy efficiency of existing energy consumption systems. An example of an energy consumption system is the heating and cooling system of an enclosure such as a home or building. According to a report from the United States Department of Energy, heating and cooling can account for 56% of the energy use in a typical home, making it a significant energy expense. Heating and cooling systems can realize greater efficiency by improving physical aspects of the system (e.g., higher efficiency furnace) and enclosure (e.g., more or better insulation). Substantial increases in energy efficiency can also be achieved through enhanced thermostat control of the heating and cooling system.
Thermostats of all types have been used to control heating and cooling systems. For example, older generation thermostats were strictly mechanical devices that used a bimetallic strip to sense temperature, and controlled an HVAC system based on the sensed temperature. The mechanical thermostats required neither electronics nor power to operate, because the strip itself would activate or deactivate circuitry within the HVAC system. This changed, however, when thermostats evolved to include electronics. Electronic thermostats, though requiring a power source in order to operate, offered more advanced HVAC control as compared to their mechanical counterparts. For example, an electronic thermostat can be programmed to have multiple temperature set points in a given day. As another example, advanced microprocessor controlled “intelligent” thermostats may have further enhanced HVAC system control capabilities. These thermostats may also be capable of connecting to computer networks, including both local area networks (or other “private” networks) and wide area networks such as the Internet (or other “public” networks), in order to obtain current and forecasted outside weather data, cooperate in so-called demand-response programs (e.g., automatic conformance with power alerts that may be issued by utility companies during periods of extreme weather), enable users to have remote access and/or control thereof through their network-connected device (e.g., smartphone, tablet computer, PC-based web browser), and other advanced functionalities that may require network connectivity.
Increases in functionality for electronic thermostats are often accompanied by increased demands for power. Accordingly, what are needed are electronic thermostats that can maximize its own power consumption efficiency depending on the HVAC system it is controlling.